Q: Thanks for your July 30 column mentioning that squirrels and raccoons are considered vectors, meaning that they are capable of spreading diseases. Does that mean we can legally trap and kill them?

A: I have written several times about how raccoons damage gardens by defecating in them, eating food crops and digging up new lawns. I also get frequent letters about squirrels that are eating up nuts and unripe fruits.

I have said that one should avoid feeding raccoons or squirrels and that raccoons are attracted by pet food or garbage in poorly covered bins. Squirrels raid bird feeders, and raccoons hunt the rats, mice and birds that feed on spilled birdseed.

From the letters, it seems clear that in some neighborhoods there are so many raccoons or squirrels that gardeners' usual tricks are not working. Raccoons smash electric-eye activated water sprayers and ignore repellent odors.

Hungry squirrels chew through plastic netting. In these cases, I have recommended contacting a county agricultural commissioner or vector control officer for help with inspections and neighborhood-wide education.

I also get letters like the above, from frustrated gardeners who do not share the qualms of some about killing animals that are pests. There are organizations working to save wild animals in our urban areas, and the most humane ways to do it involve exclusion methods such as electric fences and making human food less available. But in the interest of making sure readers understand what is legal and what is illegal and why, I will attempt to answer the question.

A county vector control officer may consider these creatures to be vectors. However, the laws covering their hunting and trapping are enforced by the California Department of Fish and Game.

Fish and Game classifies raccoons as "furbearers." Laws were created to protect them from overhunting when their fur was more valuable than at present, and raccoons less numerous. Tree squirrels, including eastern and western gray, douglas and red fox squirrels (but not northern tree squirrels, which are protected) are classified as resident small game mammals.

There are legal hunting seasons for raccoons and for tree squirrels. Trappers and hunters of either kind of animal for fur or recreation need a license and must comply with many regulations that are listed on the Fish and Game Web site (dfg.ca.gov). These hunting seasons are irrelevant to the beleaguered urban gardener, however, as hunting is likely to be prohibited by city laws.

If particular raccoons or squirrels have become a nuisance, defined as injuring growing crops or other property, different rules apply. Nuisance raccoons and red fox squirrels (the most likely nuisance squirrel species) can be killed in any season.

For more on legal means of trapping and killing nuisance animals, see the book Wildlife Pest Control Around Gardens and Homes, Second Edition, Salmon, Whisson, & Marsh, UC Davis, ANR Publication 21385, 2006, available at anrcatalog.ucdavis.edu or by calling (800) 994-8849.

The information on kinds and placement of traps for tree squirrels is especially useful. Note that it is illegal to use poison bait to kill tree squirrels in California. It is also illegal to use poison bait to kill raccoons without a permit from Fish and Game, which is highly unlikely to issue such a permit.

People who are working for an animal damage/nuisance wildlife control company need a license to hunt or trap nuisance animals. Anyone who isn't charging a fee to hunt or trap nuisance animals doesn't need such a license to do it. However, before trapping nuisance gray squirrels, you must get a depredation permit from Fish and Game.

If you have trapped a raccoon or a red fox squirrel, for whatever reason, the law is very clear about what you can do next. You can euthanize it immediately, or release it immediately "on site," that is, pretty much where you found it.

But wait, you are probably thinking, why would I want to put it back where it was? I suppose if it was in your kitchen, and released in your garden, that would be an improvement, but not if it was already wreaking havoc in your garden.

The law is clear: no relocating live raccoons or red fox squirrels, trapped because they were nuisances, to a different location. It is because they are already everywhere, and also because moving them can spread animal diseases into new areas.

It isn't necessarily more humane to relocate them, because relocated animals very often do not survive in new territories. The only exception to the above is that if the trapped raccoon or fox squirrel has immature young, a wildlife rehabilitation agency can raise the young and release them when they are mature.

Because the average citizen is not experienced in trapping, and especially not in humane and safe killing of animals, it is often better to hire a licensed and insured nuisance wildlife control operator to do it. You can find one in your local area through the Web site wildlife-removal.com. When you call, make sure your location is within its service range.

Thanks to the following state Fish and Game employees for answering my many questions: Jesse Garcia, environmental scientist in the wildlife branch; Stacy Martinelli, associate wildlife management specialist; and Jeannine DeWald, associate biologist.